﻿import java.util.HashMap;
import java.util.Hashtable;
import java.util.Iterator;
import java.util.Map;
import java.util.TreeMap;

public class JavaHashMap {
	public static void main(String[] args) {
		Map map = new HashMap();
		map.put("a", "aaa");
		map.put("b", "bbb");
		map.put("c", "ccc");
		map.put("d", "ddd");

		Iterator iterator = map.keySet().iterator();
		while (iterator.hasNext()) {
			Object key = iterator.next();
			System.out.println("map.get(key) is :" + map.get(key));
		}

		Hashtable tab = new Hashtable();
		tab.put("a", "aaa");
		tab.put("b", "bbb");
		tab.put("c", "ccc");
		tab.put("d", "ddd");
		Iterator iterator_1 = tab.keySet().iterator();
		while (iterator_1.hasNext()) {
			Object key = iterator_1.next();
			System.out.println("tab.get(key) is :" + tab.get(key));
		}

		TreeMap tmp = new TreeMap();
		tmp.put("a", "aaa");
		tmp.put("b", "bbb");
		tmp.put("c", "ccc");
		tmp.put("d", "ddd");
		Iterator iterator_2 = tmp.keySet().iterator();
		while (iterator_2.hasNext()) {
			Object key = iterator_2.next();
			System.out.println("tmp.get(key) is :" + tmp.get(key));
		}

	}
}